The present invention pertains to repositioning articles within a space that is accessible for said repositioning only during a series of periods that are separated by intervals of less accessibility for said repositioning than during said periods.
For various manufacturing and other processes it is desirable to reposition an article within a given space between processing steps. When an article has to be moved from a first processing position within the given space to a second processing position within the given space, but such movement is impeded or made impossible by changes in the accessibility of the given space for said repositioning that are necessitated by one or more aspects of the process, such repositioning typically is carried out during those periods when the given space is more accessible for said repositioning but not during those intervals when the given space is less accessible for repositioning. As a result, such accessible periods may be of such an extended duration as to slow down or halt the overall process and thereby make the overall process less efficient.
For example, in a process for injection molding a multi-component product a first component formed in a first mold cavity by injection molding is repositioned to a second mold cavity in which a second component of the product is formed in combination with the first component by injection molding the second component. Such repositioning within the space between the mold parts can be accomplished only during a period of time when the mold is open, and typically is accomplished by means of a robot arm that (a) attaches onto the first component in the first mold-cavity position with an attachment mechanism on the robot arm, (b) moves the attached first component from the first mold-cavity position to a second mold-cavity position and (c) releases the first component from the attachment mechanism. However, the time required for attaching onto the first component, moving the attached first component from the first mold-cavity position to the second mold-cavity position and releasing the first component is greater than the time required for merely attaching onto a molded article and moving the attached molded article from its mold-cavity position when repositioning of the molded article is not required, whereby such repositioning from the first mold-cavity position to the second mold-cavity position within the space between the mold parts makes it necessary to keep the mold open for a longer period of the time so that the space between the mold parts will be accessible until said repositioning is completed.